US 4716407

I'll search for this specific patent number and check for any litigation/docket activity.

Let me run additional targeted searches for litigation and USPTO records.

US Patent 4,716,407 — Analyst Summary

Search scope note: I searched Google Patents/PatentsPDF (full authoritative text provided), Justia, FreePatentsOnline, uspto.report, and general web/docket sources. I found no CAFC 2026 docket activity, no district court infringement case, and no PTAB proceeding naming U.S. Patent 4,716,407. A February 2026 Eastern District of Texas case (ImberaTek LLC v. Lenovo Group Ltd. et al., 2:2026cv00147) involves Motorola-branded defendants, but I could not confirm that 4,716,407 is among the asserted patents — treat that as unresolved, not as a match.

Bibliographic Data (from the patent document itself)

Abstract (verbatim, abridged)

"While receiving a lower priority message, a remote transceiver unit in a trunked radio communication system is diverted immediately to a priority channel when a priority message is generated. In a first embodiment, a low speed, sub-audible sync word, transmitted by a system controller, causes the remote transceiver to momentarily interrupt the current message and receive priority data transmitted by the system controller. If the priority level of the priority messages exceeds that of the current message, it immediately switches to the priority channel. If not, the remote transceiver reverts to its normal receiving mode and continues its original communication. In a second embodiment, the priority data is transmitted entirely sub-audible so as to not interrupt the current message. Lastly, in a more basic embodiment, a sub-audible word is transmitted to the remote units causing them to revert to the control channel to receive the priority call assignment. Multi-level message priority is also provided by transmitting sequential priority data words which identify calls of varying priority. The remote units may then respond to the highest priority call."

Plain-Language Overview of the Independent Claims

Claim 1 — Subscriber-side method (broadest priority-scan claim).
A subscriber unit that is already receiving a current message on a current channel: (a) receives priority data on that same current channel; (b) determines the priority level of the incoming priority message from that data; (c) compares it to the priority level of the current message; and (d) abandons the current message and responds to the priority message if the priority message's level at least exceeds that of the current message. The novelty hook is that the comparison is made by the subscriber itself, from data delivered over the channel it is already on — no dedicated priority channel and no need to monitor a separate control channel.

Claim 12 — Subscriber-side method with sync-word interrupt.
Same as Claim 1 but specifies delivery mechanics: a sub-audible sync word arrives on the current channel, the subscriber temporarily interrupts the current message, then receives the priority data, and then runs the same determine/compare/abandon logic. This maps to the "audible signalling" embodiment (Fig. 1a).

Claim 16 — Subscriber-side method with interleaved sub-audible data.
Same comparison-and-abandon logic, but the priority data arrives sub-audibly, interleaved with a connect word (i.e., the low-speed handshake), so the current call is never audibly interrupted. This maps to the "sub-audible signalling" embodiment (Fig. 1b).

Claim 19 — Expanded subscriber-side method (sync word + priority data + EOM).
Adds an end-of-message code step and makes the two branches explicit: abandon and move to the channel identified by the priority data if the new message is at least higher priority; otherwise remain on the current channel. Effectively a fully spelled-out version of Claims 1/12 with the EOM boundary.

Claim 20 — Similar to Claim 16 with explicit stay/leave branches.
Sub-audible priority data interleaved with a connect word; compare; abandon and receive the priority message if it at least exceeds the current level; otherwise remain on the current channel.

Claim 21 — Central-station-side method (alerts subscribers already on traffic channels).
The controller: (a) receives a channel request from a subscriber on a control channel; (b) generates priority data from that request; (c) transmits that priority data on each currently allocated communication channel (i.e., reaching subscribers already busy and not monitoring the control channel); and (d) transmits a channel grant on the control channel.

Claim 25 — Central-station-side method with sync word and EOM.
Same as Claim 21 but the transmission sequence includes a sub-audible sync word before the priority data and an end-of-message code after it, then the channel grant.

Claim 26 — Central-station-side method, sub-audible interleaved variant.
Same as Claim 21 but the priority data is transmitted sub-audibly, interleaved with a connect word, on every currently allocated channel.

Claim 27 — System-wide, multi-party method (idle subscriber + central station + busy subscribers).
A three-role claim: the idle subscriber requests a channel and gets a grant; the central station receives the request, generates priority data, transmits it to subscribers on each currently allocated channel, and issues the grant; each currently-communicating subscriber receives the priority data on its current channel, determines the priority level, compares it to its current message, and abandons the current message to receive the priority message if the new one at least exceeds the current level.

Claim 34 — System-wide method with full signalling sequence.
The broadest orchestration claim: combines the idle-subscriber request/grant, the central station sending a sub-audible sync word + priority data + end-of-message code on allocated channels plus the grant on the control channel, and the busy subscriber receiving all three, comparing levels, then either abandoning for the priority message or remaining on the current channel.

Claim 35 — System-wide method, fully sub-audible variant.
Same three-role structure as Claim 27, but the central station transmits the priority data sub-audibly interleaved with a connect word, the busy subscriber receives it sub-audibly, and the claim explicitly recites both branches (abandon if higher priority; remain if not).

What the Independent Claims Collectively Cover

The claim set is organized along three axes, and this is the useful takeaway for freedom-to-operate or invalidity analysis:

1. Who performs the steps — subscriber-side (1, 12, 16, 19, 20), central-station-side (21, 25, 26), or the full system/three-party combination (27, 34, 35).
2. How the priority data is delivered — audible interruption via a sub-audible sync word (12, 19, 25, 34) versus fully sub-audible interleaving with the connect word / low-speed handshake (16, 20, 26, 35) versus generic "receiving priority data on the current channel" (1, 21, 27).
3. The decision rule — the subscriber itself compares priority levels and switches only if the incoming message at least exceeds the current level; otherwise it stays. A separate, more basic embodiment (predetermined word → return to control channel → pick highest-priority call from repeated assignments) is described in the specification but is not separately claimed.

Prior-Art / Family Context (as listed on the patent page)

• Cited by (84 documents), including Motorola's own US 4,776,037 ("Method and apparatus for providing priority channel scan in a radio," 1988), US 4,905,302 and US 4,939,746 (General Electric trunked repeater systems), and US 4,965,407/US 5,087,828 (later Motorola/GE priority and channel-expansion work).
• The patent is cited as prior art in later trunked-radio filings, e.g., KR 960004810B1 ("Trunk-type radio repeater system") and JP H06-216925, consistent with its role as an early reference for in-call priority notification.

Uncertainty Flags

• No verified litigation. I could not locate any 2026 CAFC docket, district court complaint, or PTAB filing that specifically names U.S. 4,716,407. Absence of a hit in my searches is not proof of absence in PACER/docket databases I cannot fully query.
• Assignee status is sourced from Google Patents' automated listing ("Motorola Solutions Inc") and is not a legal conclusion; the recorded original assignee is Motorola, Inc.
• Continuity type is internally inconsistent between the specification ("continuation") and Google's related-application table ("Continuation-In-Part"); I have not resolved which is correct.
• Expiration is listed as 2005-10-07 by anticipation based on the 1985 priority date — the patent is long expired and not enforceable, which is relevant if anyone is contemplating assertion activity.

I'll research litigation involving US patent 4716407. Let me run several targeted searches.

Initial results are generic. Let me target litigation-specific databases and sources directly.

No litigation hits yet. Let me query litigation-specific sources directly.

Litigation Search Results: US Patent No. 4,716,407

Summary finding: No litigation involving US Patent No. 4,716,407 was identified in the sources I was able to search.

I was unable to find any district court complaint, CAFC appeal, ITC investigation, PTAB proceeding, or PTO reexamination record naming U.S. Patent No. 4,716,407 ("Trunked communication system true priority channel scan," Borras & Sasuta, issued Dec. 29, 1987, filed Dec. 19, 1986, priority Oct. 7, 1985, original assignee Motorola, Inc., now listed under [Motorola Solutions Inc.](/litigations/by-defendant/Motorola%20Solutions%20Inc.)) as an asserted or challenged patent.

What I actually searched and found

The only substantive third-party appearances of this patent that surfaced were as prior art citations, not as litigation:

• Cited in the International Search Report for WO2008115680A1 (category "A," cited at col. 4, lines 1–45).
• Cited in the International Search Report for WO1995006395A1 as category "X" against claims 1 and 3–10 (the examiner treated it as anticipating/at least highly material).
• Listed in FreePatentsOnline classification 340/7.59 (the "trunked communication system" art area).

Important caveats on this negative result

1. I could not reach the specific databases requested. Direct queries against portal.unifiedpatents.com/litigation/caselist, PACER, and RPX Insight returned no usable records within my search budget. A negative finding from my searches is therefore not equivalent to a certified search of PACER's full docket history.
2. Exhaustive tools not run. I did not complete queries against CourtListener's RECAP docket API, Docket Navigator, Lex Machina, or the ITC's EDIS database. Because the patent issued in 1987 and expired (per the Google Patents legal-status record) on October 7, 2005, any accused-infringement claims would have been time-barred no later than six years thereafter under 35 U.S.C. § 286, so any litigation would necessarily predate roughly 2011 — i.e., it would sit in pre-2012 paper/early-electronic dockets that are the least well covered by free databases.
3. Do not conflate with similarly numbered patents. My searches surfaced numerous unrelated "‘407" patents. None of the following involve US 4,716,407, and each should be treated as a distinct patent:
   • U.S. Patent No. 8,510,407 (DoDots Licensing Solutions LLC) — subject of Lenovo Holding Co., Inc. et al. v. DoDots Licensing Solutions LLC, IPR2019-01279 (PTAB) and DoDots Licensing Solutions LLC v. Lenovo Holding Co., Inc., No. 18-098-MN (D. Del.).
   • The "‘407 patent" in Tyco Healthcare Group LP v. Ethicon Endo-Surgery, Inc. (§ 102(g) invalidity).
   • The "‘407 patent" in Momentus Golf, Inc. v. Swingrite Golf Corp. (Fed. Cir. No. 05-1614).
   • The "‘407 Patent" in Sioux Steel Co. v. Prairie Land Millwright Services, Inc., No. 1:16-cv-02212 (N.D. Ill.).
   • FRCP Rule 407 evidentiary cases (Kociemba v. G.D. Searle & Co.; Hughes v. Stryker; EZPZ/LNC) — these involve the Federal Rule of Evidence, not any patent.

Related-but-distinct Motorola litigation (for context only)

Motorola Solutions has been active in trunked-radio patent litigation — most prominently Motorola Solutions, Inc. v. Hytera Communications Corp. (N.D. Ill., Case No. 1:17-cv-01973), which involves patents such as the '991, '701, and '869 patents. I could not verify that US 4,716,407 is among the patents asserted in that case, and given that the patent expired in 2005 I have no basis to believe it is. This reference is offered only to distinguish it, not to associate it.

Recommended verification steps

To obtain a definitive answer, the following should be run directly (I was unable to complete them):

1. PACER / CourtListener RECAP search on "4,716,407" and "4716407" as full-text terms in complaints.
2. Docket Navigator or Lex Machina patent-case search filtered by patent number — these index pre-2010 paper dockets more completely than free sources.
3. RPX Insight and Unified Patents Portal patent-page lookups (the Unified portal typically shows a "Litigation" tab keyed to patent number).
4. USPTO Patent Public Search → "Transactions" / "Litigation" tab and the USPTO Assignment record (which shows only the 1986 Motorola assignment per the Google Patents data; no later assignments appear, which is consistent with a patent that was never acquired for assertion).
5. Confirm the expiration date of Oct. 7, 2005 (it is listed as "Expired – Lifetime," meaning the failure to pay maintenance fees or the statutory term end terminated it), and note that this substantially limits the window in which an assertion could have occurred.

Bottom line: Based on the searches available to me, I found no known litigation involving US Patent No. 4,716,407. I cannot represent this as an exhaustive nationwide clearance, and I have flagged the specific gaps and the specific steps needed to close them.

I'll verify the structured data against the public record before drafting.

Proceedings overview

Total AIA trial proceedings on file: 0. Breakdown: 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution-denied. Per the structured "PTAB proceedings on file" block (USPTO ODP), no AIA trial has ever been indexed against US 4,716,407, and my independent web searches surfaced no IPR, PGR, or CBM proceeding naming this patent — every "‑407" hit I retrieved (IPR2019‑01279 on U.S. 8,510,407; IPR2020‑01426 on U.S. 8,287,508; the PureWick/Stellar/Motorola matters) is a different patent. The bottom-line posture for a defendant is not "hardened by IPR" — it is that the patent has been dead since 2005-10-07 and is not even eligible for the AIA regime. There is nothing for a PTAB petitioner to attack and no FWD to quote, so an IPR strategy is unavailable and unnecessary.

Note on the structured source: the ODP block states "no AIA trial proceedings" as of the most recent ingest. I treat that as the canonical answer; web search neither confirmed nor contradicted any proceeding, which is consistent with zero activity.

(No proceeding number) — no petitioner v. Motorola, Inc.

There is no proceeding to report. For completeness, the following is the legal/eligibility picture that explains why the list is empty:

• Type: N/A — no Inter Partes Review, Post-Grant Review, or Covered Business Method review exists.
• Filed: N/A.
• Status: No PTAB proceeding on file (expired – lifetime; anticipated expiration 2005-10-07 per Google Patents legal status).
• Judge panel: N/A — no panel ever designated.
• Petition grounds: N/A. For reference, the patent carries 35 claims (claims 1–35), independent claims 1, 12, 16, 19, 20, 21, 25, 26, 27, 34, 35, all drawn to trunked-radio priority-channel methods.
• Institution decision: None — none could have been instituted. IPR/PGR/CBM only became available on 2012-09-16 (AIA § 6); PGR is limited to patents with an effective filing date on or after 2013-03-16; CBM is limited to covered business method patents (financial products/services) and sunset on 2020-09-16. This patent has a 1985-10-07 priority date, is a radio-communications (H04W84/08) patent — not a CBM candidate — and its statutory term ended 2005-10-07, roughly seven years before AIA trials existed.
• Final Written Decision: None.
• Settlement / termination: N/A.
• Appeal: No Federal Circuit appeal of any PTAB FWD — there is none to appeal. I found no CAFC opinion involving U.S. 4,716,407.
• Defensive value: Zero PTAB exposure and zero PTAB benefit. The patent cannot be asserted prospectively at all; the § 286 six-year damages lookback closed in 2011, long before any current demand. A demand letter citing U.S. 4,716,407 is facially baseless — the patent expired more than 20 years ago. Note: because the patent expired, even a defensive ex parte reexamination or IPR would be largely moot; the correct response is a statute-of-limitations/expiration rejection, not a PTAB petition.

Strategic summary

Claim status — CANCELED vs. SUSTAINED vs. UNTESTED. All 35 claims (1–35) are UNTESTED before the PTAB; none has been canceled, and none has been sustained through an AIA trial. There is no narrowing whatsoever through PTAB. The claims were, however, terminated by operation of law when the patent expired on 2005-10-07 (the 20-year term measured from the 1985-10-07 priority/filing date of parent application Ser. No. 785,173 — the granted application is a continuation of that parent, which Google Patents lists as abandoned). There are therefore no "surviving claims" to assert: the entire claim set lapsed together.

Estoppel landscape. Section 315(e)(2) estoppel is irrelevant here. No party petitioned, so no petitioner (or privy) is estopped — but the mirror-image point matters more for a defendant: because no IPR was ever filed, there is no PTAB record, no IPR-estoppel shield, and no institution decision to leverage in district court. Prior-art grounds are "available" in the abstract but useless, because there is no live infringement claim for them to defeat. The real defenses are expiration (2005-10-07), the closed § 286 damages window, and laches/limitations.

Pattern signals. None. There is no repeat petitioner, no serial-IPR pattern, no patent-owner appellate aggression (Motorola, Inc. — now Motorola Solutions, Inc. — is the original assignee/current assignee, itself a serial patent owner and defendant in unrelated matters, but nothing on this patent), and no defensive aggregator (Unified Patents or similar) in the chain. The absence of any IPR is unsurprising and not itself a "signal of weakness or strength" in the usual sense — it is a consequence of the patent being a 1985-filing, 2005-expiring radio patent that predates the entire AIA trial regime.

Recommended next steps

• If you are a defendant facing assertion of 4,716,407: Do not invest in an IPR (it is time-barred in substance and moot — the patent is expired). Instead, respond on the pleadings that the patent expired 2005-10-07 and that any infringement claim is barred by 35 U.S.C. § 286 (six-year lookback) and laches. The Google Patents legal-status page records "Anticipated expiration 2005-10-07" and status "Expired – Lifetime" — see https://patents.google.com/patent/US4716407/en. There is no FWD to cite, because none exists.
• If you are evaluating the patent for acquisition or licensing: Value is nominal/zero — expired, unenforceable prospectively, no PTAB-surviving claims.
• If you want to double-check the absence of PTAB activity yourself: Search the PTAB E2E system (https://ptacts.uspto.gov/) and the USPTO Patent Trial and Appeal Board End-to-End docket by patent number 4,716,407; you should find no IPR/PGR/CBM entries, and a District Court / CourtListener check (https://www.courtlistener.com/) should show no live assertion.
• Plain statement: There is no PTAB activity on file for US 4,716,407, and none is legally possible going forward. The absence here is not the usual "well-asserted patents eventually attract IPRs" signal — it reflects a patent whose term ended before the AIA existed.

Confidence note: I have high confidence in the zero-proceeding conclusion based on the structured ODP block plus web search. I could not verify the existence of any pre-AIA interference or ex parte reexamination from the sources retrieved; the Google Patents record shows no reexamination certificate, but I have not independently confirmed that with the USPTO file wrapper, so I flag it rather than assert it.

I'll research the assignment record for this patent. Let me run targeted searches against USPTO Assignment Center and related sources.

Let me query specific ownership-record sources and the Google Patents legal-events tab.

Assignment / Ownership Chain Analysis — US Patent 4,716,407

Source-access note (read first). The USPTO Assignment Center (assignmentcenter.uspto.gov) and Assignments-on-the-Web (assignment.uspto.gov) are JavaScript applications that are not crawled/indexed by general web search, and I could not open a direct query against them within this session. Consequently I was able to confirm the existence and content of one recorded assignment (the original inventor→Motorola transfer, mirrored in the Google Patents "Legal Events"/reassignment record) but I could not retrieve its reel/frame number or the correspondent of record. I am flagging every field I could not verify rather than estimating it. A "not retrieved" is a tooling gap here, not a finding that no record exists.

Inventors

• The application (Ser. No. 06/945,210, filed 1986-12-19) is stated in the specification to be a continuation of Ser. No. 785,173, filed 1985-10-07, now abandoned. Both named inventors are consistent across the family per the Google Patents record.
• Unusual patterns: None observed. There is no evidence in the record I could retrieve that either inventor departed Motorola within 12 months of filing, and no evidence of a later inventor-side transfer. I did not independently verify inventor employment history or departure dates, so this is "no signal found," not "confirmed negative." Motorola in this era routinely took pre-issuance assignments from employee-inventors, and this one was recorded on/near the 1986-12-19 filing date — the ordinary pattern, not a fire-sale precursor.

Cross-reference flag: The previously generated summary noted that the specification says "continuation" while Google's related-application table labels Ser. No. 785,173 a Continuation-In-Part. I also cannot reconcile it. It does not affect ownership: both the parent and the child were Motorola-originated employee inventions, and the single recorded assignment covers the assignors' interest.

Original assignee

Motorola, Inc. (name as recorded on the issuance-era assignment; the Google Patents citation tables for this patent likewise list the assignee as "Motorola, Inc.").

• Primary line of business: Land-mobile two-way radio and trunked radio systems — this patent sits squarely in Motorola's core trunked-repeater/systems product line (priority-channel scan for trunked systems, per the specification's own framing at col. 2 ff.).
• Did they ship a product embodying the claims? Yes, in substance — the disclosure describes the system controller (Fig. 3) and subscriber unit (Fig. 2) architecture Motorola deployed in its trunked radio systems of the era, and the patent's claims are directed at the call-handling methods those systems implement. I have not independently documented a specific commercial model number from this session, so treat "shipped a product" as high-confidence-by-context rather than a citation to a product manual.
• Current status: Motorola, Inc. did not dissolve and was not sold. It is the same legal entity that, effective 2011-01-04, changed its corporate name to Motorola Solutions, Inc. (the mobile-devices business was separately spun off as Motorola Mobility Holdings, Inc.). Motorola Solutions, Inc. remains an active, publicly traded operating company (NYSE: MSI). Search results corroborate the 2011-01-04 name-change date and Motorola Solutions' active corporate registration.
• Caveat on the "current assignee" label: The prior section reported Google Patents' "Current Assignee" field as "Motorola Solutions Inc" and correctly flagged it as not a legal conclusion. Note that the Legal Events list in the authoritative patent text contains no change-of-name record for this patent — it shows only the 1986 Motorola assignment, grant (1987-12-29) and anticipated expiration (2005-10-07). Google has therefore most likely inferred the successor by corporate-name matching rather than by a recorded instrument. Whether a blanket Motorola→Motorola Solutions change-of-name instrument specifically names this patent is unclear and should be verified at the Assignment Center.

Assignment timeline

Retrieved records: 1. Post-issuance assignments: 0.

• 1986-12-19 (recorded) — Reel/Frame: NOT RETRIEVED (tooling limitation — see source-access note)
  • Conveyance: Assignment of assignors' interest ("ASSIGNMENT OF ASSIGNORS INTEREST"; Google legal-event label "reassignment")
  • Assignor: Jaime A. Borras; Michael D. Sasuta
  • Assignee: Motorola, Inc. (Delaware)
  • Correspondent: NOT RETRIEVED — cannot assess recurrence.
  • Context: Ordinary pre-issuance employee-inventor assignment to the operating employer; not an acquisition, fire-sale, reorg, securitization, asserter transfer, or defensive aggregation. Recorded contemporaneously with the 1986-12-19 filing of Ser. No. 06/945,210.

Important: Beyond this single instrument, the Assignment Center-visible chain (as mirrored in the patent's legal events) shows no further assignment of record for this patent. There is no security agreement, no merger, no license, no release, no correction, and no post-issuance transfer. If the Assignment Center in fact holds additional records I could not reach, this section should be re-run before reliance.

Additional title-relevant event (not an assignment): the statutory term ended and the patent is listed "Expired – Lifetime" with anticipated expiration 2005-10-07 (20 years from the 1985-10-07 priority date; the alternative 17-years-from-issue date would have been 2004-12-29). Either way the patent lapsed before the 2011 Motorola name change and is unenforceable — which is why a later "current assignee" label has no practical assertion significance.

Timeline diagram

timeline
    title Ownership of US 4716407
    1985 : Parent application 785173 filed
    1986 : Continuation 945210 filed
         : Inventors assign rights to Motorola Inc
    1987 : Patent 4716407 issues 29 Dec
    2005 : Patent term ends 07 Oct
    2011 : Motorola Inc name changed to Motorola Solutions

NPE / troll-pattern signals

Corroborating non-ownership activity (builds on the prior section): The only third-party uses of this patent I could confirm are prior-art citations, not assertions — e.g., the WO 1995/006395 International Search Report cites US 4,716,407 as category "X" against claims 1 and 3–10 of that application, and it appears as an "A" citation in WO 2008/115680 A1. Being cited as invalidating art is the mirror-image of being asserted: it shows the '407 as a blocker to others, never as a plaintiff's weapon.

Verdict

Insufficient data — and the substance behind that label is not ambiguity about an NPE chain; it is that the only recorded link is the original 1986 inventor→Motorola assignment and there is no post-issuance transfer of record. Under the rubric this maps exactly to "no records, or only the original assignment." The single entry (1986-12-19, Assignment of assignors' interest, Borras/Sasuta → Motorola, Inc.) is an ordinary employee-inventor assignment to an operating manufacturer; the chain then runs straight to term expiration on 2005-10-07 with no shell transfer, no known asserter, no cascading LLCs, no pre-suit transfer, no bankruptcy sale, and no defensive-aggregator endpoint. On the evidence available, this patent never entered an NPE chain — but because I could not retrieve the reel/frame or correspondent and could not query the Assignment Center directly, I will not upgrade the call to "Defensive / non-asserting" (which requires a verified terminal record) or to any NPE tier.

Verify at:

• USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent number 4716407; use the "Search by Patent Number" and then the "Properties" tab to pull the full reel/frame chain and correspondents)
• USPTO Assignments on the Web — https://assignment.uspto.gov/patent/index.html
• Google Patents legal events (mirror used in the authoritative text) — https://patents.google.com/patent/US4716407/en

Fields still open for the next pass: (i) reel/frame and execution date of the 1986 assignment; (ii) correspondent of record on that instrument; (iii) existence, if any, of a recorded Motorola→Motorola Solutions change-of-name instrument naming this patent (Google's event list shows none); (iv) confirmation that the Assignment Center holds no other records, including any pre-1980-adjacent or corrected entries.

I'll search the USPTO and patent databases specifically for this patent and, critically, for the references cited in it (its prior-art citations), since the "Cited By" list is a different relationship (later art citing the '407 patent).

The main Google Patents fetch omitted the "Citations" (prior-art references cited in the '407 patent) section. Let me pull that section specifically from multiple sources.

I now have the start of the "References Cited" (prior-art) list. Let me get the complete list from the front page of the patent and Justia.

I hit the search-step limit before I could retrieve the complete "References Cited" list, so I'm answering with what I could actually verify and flagging the gap explicitly rather than filling it by inference.

Most Relevant Prior Art for U.S. Patent 4,716,407

1. USPTO-record confirmation (the specific number, not a lookalike)

The number 4716407 resolves cleanly and exactly to:

Sources: https://patents.google.com/patent/US4716407/en, https://patents.justia.com/patent/4716407, https://uspto.report/patent/grant/4716407. No other patent number was substituted. (Note the adjacent Motorola case, US 4,776,037, is a separate patent.)

2. Critical terminology check before the §102 analysis

"Citations for 4716407" resolves to two different, unrelated sets, and only one is prior art:

Everything in the "Cited By (84)" block and in the WO2008115680A1 / WO1995006395A1 search reports is downstream art. It has no §102 effect on '407 and should not be charted as such.

3. References Cited — what I could retrieve

From the Justia "Referenced Cited → U.S. Patent Documents" listing (https://patents.justia.com/patent/4716407), the front-page prior-art list begins as follows. The listing truncated at entry 8 ("4…") in my retrieval, so the remaining U.S. entries and any foreign documents are not captured below. I am not filling those in from memory.

Important caveat on the titles/descriptions in rows 2–7: I did not independently verify those titles; only row 1 (Gallagher) is confirmed, because the same Gallagher patent surfaces as "Multi-frequency receiver with automatic channel selection and priority channel monitoring (1967)" on the SciSpace record and sits in the same family line as the '407 reference list. Rows 2–7 are identified only by number/date/inventor exactly as the front page lists them (assumption: these are the examiner's early "scanning radio" citations, which the '407 specification itself characterizes as the known background art).

4. Provisional §102 assessment (preliminary — not a validity opinion)

Reading the confirmed and retrieved citations against the claim structure set out in the earlier section:

• Claim 1 (broadest subscriber method) — requires the subscriber to (a) receive priority data on the current communication channel, (b) determine the priority level, (c) compare it to the current message, and (d) abandon the current message if the new one at least exceeds it. The cited U.S. scan patents (Gallagher et al.) are conventional "dedicated priority channel" scanning — they sample a separate priority channel for carrier/activity; they do not deliver priority data on the current channel and do not have the subscriber compare priority levels. So as a group they are background/dedicated-priority-channel art, and on the record available to me they do not appear to anticipate claim 1 under §102. They are, at most, §103 fodder for the preamble.
• Claims 6–8, 11 (returning to control channel; verification signal; mode switching) — the classic scan-receiver structure in these references is closer to the "receive a signal on another channel and switch" mechanics, so these references are the most likely §102 candidates for those narrow sub-claims, though I could not verify element-by-element without full text.
• Claims 12–20 and 21–35 (sub-audible sync word interrupt; sub-audible priority data interleaved with the connect word/LSH; central-station broadcast of priority data on all allocated channels) — none of the retrieved references disclose sub-audible interleaving of priority data with a low-speed handshake, so they should not be charted as anticipatory for these claims.
• The single most-likely-anticipatory reference cannot be confirmed, because I could not retrieve which entries carry the examiner's asterisk (the "*" used on the front page to mark the most pertinent references).

Bottom line for §102: the cited U.S. patents are consistent with the background art the '407 specification itself concedes ("In conventional non-trunked communication systems, 'priority scan' is accomplished by the use of a dedicated priority channel…") — i.e., they go to the field and the preamble, not to the distinguishing comparison-and-switch-on-current-channel features of claims 1 and 12–35. The claims were allowed over this art.

5. Cross-reference to the earlier sections

• This section adds the front-page prior-art list that the earlier "Patent summary" and "Litigation summary" did not include. No contradiction with those sections.
• The earlier "Cited By (84)" reproduction is not prior art; I want to make that explicit because it is the list most readily confused with "citations for 4716407."
• The continuity discrepancy flagged earlier (spec says "continuation of Ser. No. 785,173"; Google's related-application table says "Continuation-In-Part") does not change the prior-art date here — priority is Oct. 7, 1985 either way, so §102 art must pre-date that.

6. Uncertainty flags and remaining work

1. Incomplete list. The "References Cited" set was truncated at entry 8. The remaining U.S. entries and any foreign patent documents were not retrieved. Do not treat the seven rows above as the complete citation list.
2. Titles unverified for rows 2–7. Only row 1 is confirmed from a second source.
3. No star/asterisk map. The examiner's designation of the most pertinent reference(s) was not retrievable.
4. Anticipation is unproven. No reference I retrieved discloses the "priority data on the current channel + subscriber-side level comparison + abandon-if-equal-or-higher" combination; my §102 mapping for the narrow sub-claims is provisional.

To close the gap, run directly: (1) USPTO Patent Center / Patent Public Search → US 4,716,407 → "References Cited" (both U.S. and foreign); (2) the front-page images of the patent PDF (patentimages.storage.googleapis.com/.../US4716407.pdf, page 1) for the asterisked entries and the two "Examiner" / "Primary Examiner" lines; (3) a Derwent/Espacenet family view to capture foreign citations not shown by Google Patents/Justia.

Net answer: The specific number 4716407 = US 4,716,407 (Borras & Sasuta, Motorola) is confirmed in the USPTO record. The prior art cited in it is a set of pre-1985 channel-scanning/priority-monitoring receiver patents — the earliest confirmed being US 3,497,813 (Gallagher, Feb. 1970) — and these function as background art for the preamble of the independent claims, not as §102 anticipation of the '407 claims' distinguishing "priority data on the current channel + self-comparison + switch if equal-or-higher" features. I could not retrieve the full list, so this is a partial, explicitly-caveated answer rather than a complete anticipation chart.

I'll first pull the actual prior-art references cited on this patent's face (the "Patent Citations" / "References Cited" section), since the provided page text only shows the forward "Cited By" list.

The provided page text omits the front-page "References Cited" list. Let me try to retrieve the examiner-cited prior art (the § 103 combinations must be built from real references).

Let me try to retrieve the front-page cited references directly from patent databases.

Obviousness Analysis Under 35 U.S.C. § 103 — US 4,716,407 (Borras & Sasuta, Motorola)

0. Threshold problem with the source material — read this first

The "Prior Art" content on the provided page is not prior art in the § 102/§ 103 sense, and the true examiner citations were not retrievable.

What the Google Patents page actually supplies as "prior art" is:

1. "Prior art keywords" — priority, message, channel, current, receiving. These are machine-generated keyword tags, not references.
2. "Cited By (84)" — a forward citation list (documents that cite '407 later). Every entry I could date post-dates '407: US 4,776,037 (filed 1987-08-03, issued 1988-10-04), US 4,905,302 and US 4,939,746 (both filed 1987-06-03), US 4,965,407 (1989), US 5,087,828 (1988), US 5,125,102 / US 5,125,103 (1990–1992), US 4,856,083 (1987), US 5,282,832-class art, etc. None of these can be used in a § 103 combination against '407. They are useful only as evidence of the art's later trajectory, and treating them as prior art would be a reversible analytical error.

I also could not retrieve the front-page [56] References Cited list (the provided page text omits it, and my retrieval attempts returned only the abstract/disclosure text of the PDF). I therefore do not know what the examiner actually cited. Rather than fabricate examiner citations, I build the § 103 case below from (a) applicant-admitted prior art inside the '407 specification itself — authoritative, since it is the patent's own text — and (b) real, date-verified references I could surface in this session, each flagged for verification status. Anything I could not date-verify is marked ⚠.

1. Legal framework and critical date

• Governing law: pre-AIA § 103 (effective filing well before 2013-03-16), so pre-AIA § 102 prior-art categories apply (notably § 102(a), (b), (e)).
• Critical date: the '407 specification states: "This is a continuation of application Ser. No. 785,173, filed Oct. 7, 1985, now abandoned." → 1985-10-07. The granted application was filed 1986-12-19. The earlier-generated bibliographic section flagged that Google's related-application table labels the parent a Continuation-In-Part, which contradicts "continuation" in the specification. This discrepancy is outcome-determinative for § 103 and I carry it forward rather than resolving it:
  • If the claims are supported in the 1985 parent → prior art must predate 1985-10-07.
  • If any limitation (most plausibly the fully sub-audible interleaving embodiment underlying claims 16, 20, 26, 31–32, 35) is new matter added in the 1986 CIP → those claims get 1986-12-19, which pulls in a larger body of art (e.g., US 4,553,263, 4,554,677, 4,573,207, all issued late 1985/early 1986).
• Level of ordinary skill (proposed): a B.S. in electrical engineering (or equivalent) plus 2–3 years of experience in land-mobile/trunked radio design; familiarity with FM two-way radio, sub-audible signalling (connect tone / CTCSS, digital low-speed handshake), trunked control-channel grant protocols, and scanning-receiver channel-monitoring logic. The '407 specification itself equates the artisan with routine knowledge of "a well known single conversion FM receiver," "a well known frequency synthesizer," etc.
• Frameworks applied: KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (predictable use of prior-art elements; "finite number of identified, predictable solutions"; design incentive); the TSM test as a factor, not a rigid requirement; MPEP 2144.04 (design choice, substitution of known technique, "obvious to try"); and In re Fressola / MPEP 2129 for applicant admissions as prior art.

2. The claimed subject matter, decomposed for § 103

Building on the earlier claim summary (not repeated), the limitations that actually need art are only these:

The only genuinely novel kernel is L5 + L6: in-band, on-channel delivery of a level that the subscriber itself evaluates. L2–L4 and L7–L8 are transport and housekeeping.

3. The prior art available to combine

3a. Applicant admissions in the '407 specification (authoritative, no external citation needed)

A1 + A2 alone disclose every element of claim 1 except a level comparison (L5/L6): a receiver on a channel, monitoring another channel's activity, and switching. The gap is one step.

3b. Verified real references (dates as surfaced in this session; ⚠ = confirm on front page)

4. The § 103 combinations

Combination A — A1 (dedicated-channel priority scan) + A2/A3 (trunked control grant with sub-audible LSH) + the queuing art (RE32,789 or US 4,553,263 family)

Renders obvious: claims 1, 4, 5, 6, 9, 10, 11, 16, 18, 20, 21, 24, 26, 27, 31–33, 35 (and 12–15, 19 if L4 is added).

• A1 supplies L2 (monitor while busy), L7 (switch and remain), and the abandon-on-activity decision.
• A2 supplies L1 (request → grant on control channel) and the control-channel identifier mechanism.
• A3/A4/A5 supply L3 and the delivery vehicle: a sub-audible digital word already transmitted by the central station on every active outbound channel, and already parsed by every subscriber's low-speed filter chain. Adding a priority-data field to a word the system already broadcasts requires no new hardware.
• RE32,789 / the queued repeater family supply the priority level abstraction and the notion that the central station assigns service according to level.

Motivation (strong, and supplied largely by the patentee): the '407 Background states the exact problem and the exact commercial need — subscribers on a traffic channel cannot hear control-channel priority commands and "have usually missed the entire priority message." The '407's own stated objects (conserve spectrum; eliminate the dedicated priority channel; serve multiple simultaneous priority messages) are design incentives the artisan would read as a mandate to move the announcement in-band. Because the LSH path already exists on every working channel (A4), using it to carry the announcement is the "finite number of identified, predictable solutions" situation of KSR: the artisan had (i) tune away to a dedicated channel, or (ii) tag the announcement onto the existing sub-audible word — and option (ii) is exactly what the specification disparages option (i) in favor of.

Reasonable expectation of success: high; the specification's own controller implementation reuses low-speed filter 226 → switch 224 → high-speed filter 228 → summing amplifier 214 → transmitter 206, i.e., the existing LSH chain, with the only change being processor 222's data content.

Combination B — A1/A2 + US 4,498,194 (or US 4,573,210 / RE33,157) + a sync-word/two-mode receiver teaching

Renders obvious: claims 2, 3, 12, 13, 14, 15, 19, 22, 23, 25, 28, 29, 30, 34.

• US 4,498,194 / US 4,573,210 supply the "tune/sample during a pause in the non-priority transmission" mechanism = L4 ("interrupting, temporarily, the current message").
• The sync-word-and-mode-switch element (claim 12(a), 19(a)) is the admitted mechanism by which a receiver is alerted to an imminent high-speed burst; a synchronization preamble preceding a data burst on the same channel is one of the oldest and most predictable techniques in digital radio, and the scanning art already teaches pausing the audio during the check interval.

Motivation: the pause already occurs in the priority-scan art; the only question is what the receiver does during the pause. Substituting a data burst for a bare carrier-activity check is a substitution of a known technique to obtain a predictable result (MPEP 2144.04(V)) — you get more information for the same audio hole.

Combination C — A2 + queuing art, for the central-station claims (21, 25, 26)

L1 is fully met by the trunked controller art: request on control channel → generate a code → transmit on allocated channels → grant. The '407 controller architecture is described as literally replicated per channel ("all the elements in FIG. 3, except processor 222, are duplicated for each channel"), so broadcasting the same word across allocated channels is a scale-up of a known per-channel function, i.e., a predictable result with no new structure. No reference beyond A2 + A4 is needed.

Combination D — A1 + A2 + A5/A6, for claims 7 and 8

• Claim 7 (receive the priority message on the channel identified by the priority data) is a substitution of one known signalling location for another: the trunked art puts the target-channel identifier in the control-channel grant; '407 puts it in the in-band word. Both are "move to channel X" messages, and the receiver hardware (synthesizer 133, counter 132, injection filter/switch 136) is identical. In re Kuhle-style obviousness of location/placement.
• Claim 8 (verification signal on the new channel) is met by the admitted LSH, which the specification itself calls a connect word whose absence causes return to the control channel; independent handshake/confirmation on a newly assigned channel was routine in the queued-repeater art.

Combination E — for the decision-rule nuances (claims 9, 10, 15, 18, 19(h), 20(e), 33, 34(p), 35(l))

The "stay if the new message is equal or lower" branch is a binary design choice between two disclosed alternatives, and the specification itself recites both alternatives — including treating an equal-priority message as "stay" (claim 10). Under KSR and MPEP 2144.04(IV), selecting one of two known outcomes is not inventive where the result is a predictable tradeoff (avoiding needless channel changes vs. never missing a same-rank message).

5. Claim-by-claim § 103 exposure summary

Best single-reference challenge: combination C against claims 21/25/26 (controller-side), where the only added step is "generate priority data from the request," a step the admitted control-channel grant already performs in substance.

Hardest claims to invalidate: 1, 5, 16, 20, 35 — because L5 (subscriber-side level comparison) is the point at which the pre-1985 scanning art stops (it detects activity, not rank). Any invalidity theory must land the reference teaching rank-based abandonment.

6. What the patent owner would argue (and how it holds up)

1. "The prior art scans a dedicated channel; trunked radios cannot scan because they must stay on the assigned voice channel." Weak: the advantage of staying is exactly what A4 undermines — the LSH is already broadcast on the working channel, so no tuning away is required. Also, '407's own claims 6 and 11 preserve the tuning-away option.
2. "The scanning art teaches activity detection, not priority-level comparison." The strongest argument, and it survives for claim 1 in its broadest reading. It is overcome only when rank-based art (RE32,789; US 4,553,263 family) is combined, so the attack depends on the queuing art being analogous. The '407's own A6 (multi-level priority codes) is an admission that ranking was known.
3. "Teaching away": the scanning art is for conventional, not trunked, systems. Not a true teaching-away (no reference disparages in-band announcement); moreover, '407 disparages its own closest prior art (the dedicated channel) as spectrum-wasteful — a disparagement that favours the modification, not away from it.
4. Secondary considerations. No verified evidence of nexus to the claimed subject matter is available to me. Any commercial-success argument (e.g., Motorola's SMARTNET/Privacy Plus "priority monitor" feature — a later Motorola patent, US 5,806,002, expressly credits '407's priority-monitor function) would need a nexus showing that the claimed level-comparison drove the sales, and would have to be commensurate with the breadth of claims 1/12/16. I have no evidence of copying, licensing, or industry praise in my sources, and the patent's own later prosecution history is not something I retrieved. Treat secondary considerations as unproven.
5. “Obviousness cannot be based on the applicant’s own disclosure.” Legally wrong as stated: admissions are usable as prior art (MPEP 2129), and here they supply the entire problem statement plus A1–A4.

7. Confidence, gaps, and cross-references

• Confidence: I am high-confidence that (i) the forward "Cited By" documents cannot be used as § 103 art against '407, and (ii) claims 2/3/6/12–15/19/21/25/26 are exposed to strong two-reference § 103 attacks. I am moderate-confidence on claims 1, 5, 16, 20, 27, 34, 35, where the level-comparison limitation creates a genuine (but bridgeable) gap.
• Gap: I did not retrieve the examiner's actual [56] citations. The specific combinations a USPTO examiner would have used in 1986–87 are unknown to me. To close this, pull the front page of the granted patent (US 4,716,407 PDF, page 1) or the file wrapper via USPTO Patent Public Search / Global Dossier, and check whether the examiner actually cited Reissue 32,789, the queued-community-repeater family, and the 4,498,194-class scanning art — that will sharpen or blunt each combination above.
• Two literal-reading flags carried forward (no auto-correction applied):
  • Continuity: the specification says "continuation"; Google's table says Continuation-In-Part. Unresolved, and material to the critical date for the sub-audible-interleaving claims.
  • Reference-numeral reuse in the specification: "26" denotes both the low-speed sync word and voice modulation; "197" denotes the subscriber processor but is once used for the system controller's handshake generation. These are § 112/claim-construction issues, not § 103, but they matter if anyone ever construes these claims.
• Practical relevance: per the previously generated sections, US 4,716,407 is Expired – Lifetime (anticipated expiration 2005-10-07), with no district court litigation and no PTAB proceeding identified. This § 103 analysis is therefore academic/defensive — its live uses are (a) assessing '407's validity where it is cited as prior art against others (e.g., category "X" in the ISR for WO1995006395A1), and (b) portfolio/valuation diligence, where the conclusion above (claims 1/5/16/20/27/34/35 vulnerable to two-reference § 103; claims 2/3/6/12–15/19/21/25/26 highly vulnerable) materially depresses any residual value.

Sources cited: the '407 specification, abstract, and claims (as supplied); Google Patents listing at https://patents.google.com/patent/US4716407/en; FreePatentsOnline class 455/166.2 listing (https://www.freepatentsonline.com/CCL-455-166.2-p3.html) and class 340/7.59 listing; Google Patents "Similar Documents" for DE2039436A1 and US5542108A; US5806002 (expressly incorporating US 4,716,407). All reference dates marked ⚠ should be confirmed against the respective front pages before being relied on in a legal filing.